This dissertation examines the role of ideologies of knowledge for the legitimization of international treaty verification at the International Atomic Energy Agency’s Department of Safeguards. Political legitimacy—and thus the organization’s effectiveness in carrying out its mandate—I argue, depends at the IAEA on the felicitous performance of “technical independence:” the making of judgments ostensibly free from political considerations. I argue further that what undergirds this performance is the regimentation of verification practices by an epistemic ideology of bureaucratic objectivity. Under this Weberian ideology, the bureaucracy is imagined to be capable of producing impartial technical knowledge through a rationalistic, rule-bound system of procedures by which individual bureaucrats are turned into disinterested actors, their threatening subjectivities contained by process. I show that the ideological success of bureaucratic objectivity provided the political conditions of possibility for the implementation of an international system to control the spread of nuclear weapons. But bureaucracy imagined as a neutral form, I contend, also permits the maintenance of a global nuclear hierarchy of “haves and have nots” and indeed, naturalizes this distinction as technocratic legal fact. The IAEA’s Department of Safeguards verifies nuclear material and nuclear activities in individual states as part of its obligations to the 1970 Non-Proliferation Treaty, which carved up the world into states permitted to possess nuclear weapons and states who forswear weapons in exchange for the promise of nuclear power. In the early 1990s, the discovery that Iraq had clandestinely pursued a nuclear weapons program produced a crisis of confidence in IAEA safeguards. Since then, the IAEA has transformed its safeguards system with additional legal instruments, technical tools, and a more expansive analytic methodology that purports to evaluate the “state as a whole.” This methodology has, in recent years, been criticized by member states who worry that the inclusion of more qualitative knowledge invites politicization, and who insist on maintaining an “objective, technical” basis for evaluating state compliance with safeguards agreements. The political legitimacy of the IAEA Secretariat, grounded in technocratic neutrality, is threatened when the organization’s expertise is no longer considered authoritative. The study is based on 18 months of fieldwork at and around the IAEA headquarters in Vienna, Austria, as well as archival research at the IAEA archive and the US National Archives. Through observation of inspector training courses, a mock inspection, and interviews with inspectors, analysts, managers, translators, and support staff I examine the nuclear safeguards project to illuminate the ways in which these actors negotiate the technopolitical tensions of their everyday work. By bringing a semiotic analysis of bureaucratic practices to bear on questions of knowledge production and expertise as articulated in the history and social study of science, this work theorizes the production of knowledge as a fundamentally communicative enterprise. In considering the practices, objects, and discourses of the IAEA’s multilingual and multinational nuclear bureaucrats, this work contributes to understanding the core possibilities of organizations in international governance, and reveals bureaucratic strategies for negotiating the boundaries of epistemic ideologies in moments of crisis.